1. Field of the Invention
The present invention relates to the separation of chemical species and, more particularly, to utilizing vortex separation to provide separation of chemical species in a mixture.
2. Description of the Related Art
Separation processes are one of the most widely used industrial processes, especially in chemical and petrochemical industries. Such separation processes are also one of the most expensive industrial processes. They require costly capital investments such as distillation columns and high utility expenditures for both heating and cooling. Currently, the fractional distillation process is almost exclusively used for separation of species with high process rates. Other low flow rate processes, such as membrane, ion exchange, etc. are available with limited applications.
Separation of hot gases and cold gases by vortex separation methods is known. A single phase (gas) and single component (pure nitrogen, for example) vortex tube is known as the Ranqe-Hilsch tube illustrated in FIGS. 1a and 1b (Prior Art), designated generally as 1. In the tube, compressed gas is introduced through the nozzle 2 which is directed tangential to the tube. The gas generates a vortex as it travels into the center of the tube and propagates through the tube.
As the gas travels into the center of the vortex, the velocity of the gas increases due to the pressure gradient. The velocity is eventually reduced as the gas travels further into the tube center because the viscosity of the gas slows the fluid.
When the gas slows down in the center of the vortex, the gas has to surrender its kinetic energy. Kinetic energy in the vortex tube is released by transferring the energy from the inner to outer vortex. Thus, the energy separation occurs between the inner and outer vortex causing the temperature differential between the cold inner and hot outer vortex. The result of such an energy separation is that the hot gas 3 is directed in a first direction and cold gas 4 is directed in an opposite second direction.
Although the use of this Ranqe-Hilsch tube 1 is useful for refrigeration applications, it is not useful for providing separation of chemical species.